1. Field of the Invention
This invention relates to a gas insulated switchgear, and particularly, to a gas insulated switchgear, capable of obviating degradation of an insulation performance by accumulating metal particles, which are generated due to friction among metal components included in the switchgear, in a predetermined space, during a process of a movable contact being moved to contact with or separated from a stationary contact.
2. Background of the Invention
A gas insulated switchgear or a gas insulated circuit breaker is an electric device, which is installed on an electric line, on which a super high voltage higher than several ten kilovolts to several hundreds kilovolts flows, so as to safely break the line automatically when the line is deliberately switched on or off in a normal usage state or a large current is generated due to a ground fault or electric shortage of the line, thereby protecting power systems or the like. The gas insulated switchgear may disperse (scatter) extinguishing gas (e.g., sulfur hexafluoride (SF6) gas or nitrogen gas), which has been compressed in a compression chamber and has high insulation force, via a nozzle upon a trip operation of the switchgear, thereby extinguishing arc generated between contacts upon the trip operation.
However, during operation of the gas insulated switchgear, the movable contact and the stationary contact are repeatedly contacted or separated each other. During the repetition, metal components included in the gas insulated switchgear are also repeatedly moved within a particular distance for operating those contacts, thereby causing friction due to contact therebetween. Upon the friction being generated between the metal components, fine metal particles are generated therebetween. Such metal particles are accumulated within an inner space of the switchgear, thereby causing a fatal problem in an insulation performance of the switchgear.
The metal particles have bad influences on the insulation performance regardless of size or entire amount thereof. Hence, it is ideal to substantially obviate the generation of the metal particles. However, the metal particles are inevitably generated at a conductive unit made of a metal. Consequently, a configuration, in which the metal particles generated in response to the repetition of the switchgear are not allowed to affect the insulation performance, is required.